Liner for concrete footing and method

ABSTRACT

A footing liner is provided to preserve and maintain the design of a footing dug in ground in accordance with the engineering and architectural specifications. The liner for footing is disposable inside the trench for receiving concrete slurry, when set forming a concrete footing forms inside the liner. The liner comprises a channel and a pair of upwardly extending walls connected to the channel for holding the slurry therein. One of the walls includes a sloping portion, which extends inwardly of the perimeter to form a perimeter liner while an interior liner includes two sloping walls. Another embodiment of the perimeter liner is for brick veneer, steel and prefabricated buildings.

CROSS REFERENCE TO REALTED APPLICATIONS

[0001] Not Applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not Applicable.

REFRENCE TO A MICORFICHE APPENDIX

[0003] Not Applicable.

BACKGROUND OF THE INVENTION

[0004] 1. Field of the Invention

[0005] The present invention relates generally to masonry building or a frame structure or a combination, and in particular to constructing a concrete slab for a building. The invention is equally applicable to brick veneer, steel and pre-fabricated building.

[0006] 2. Description of Related Art

[0007] In constructing a concrete slab, builders typically dig a trench in the ground to lay a footing. The trench has the specific dimensions and shape of the footing specified in the building plan. The footing is generally of two types, a perimeter and an interior load bearing one. The perimeter footing has a lower portion and a pair of walls connected to the lower potion and extending upwardly. One of the walls extends upwardly to the ground level, and the other wall extends vertically and then inclines at an angle terminating in a horizontal portion at the ground level. The interior bearing footing has a lower portion and a pair of walls connected to the lower portion. Both walls extend vertically and then incline at an angle terminating in a horizontal portion on the ground level, which becomes the bottom of a concrete slab.

[0008] Builders strive to produce a footing that has the specified design set by engineers. It is possible to prepare a footing in the soil according to the engineering specifications. However, maintaining theses specification is not possible because unstable soil conditions make it virtually impossible to maintain the specific design. Dirt falls into the base of the footing from collapsing walls of the footing, which widens the base of the footing. As a result, the designed depth of the footing is reduced. Additionally, irregularities of the soil make it difficult to obtain the exact design in accordance with the engineering specifications. Falling rain causes surface soil to move and fall into the base of the footing, thus changing the shape of the footing.

[0009] To accommodate theses deformations in the shape of the footing, builders pour additional amounts of slurry, which results in wasting quantities of cement. Also, builders may add extra quantities of water to the slurry, which compromises the predetermined strength of the resulting concrete. Furthermore, footings that do not meet the required strength test may prove to be safety threat, and need to be destroyed and rebuilt.

[0010] From the foregoing, it is apparent that there is a critical need for a footing liner that preserves the specific shape and design of the concrete footing.

BRIEF SUMMARY OF THE INVENTION

[0011] The present invention relates to a footing liner for preserving shape and design of a concrete footing and method for installing the same. The liner is disposable inside a trench dug in the ground for receiving slurry therein. The liner functions as a mold for slurry and permits setting into the desired shape of the concrete footing. The liner substantially conforms in shape to the footing trench dug in the ground. A perimeter footing liner includes a lower portion such as a channel, and a pair of upwardly extending walls connected to the lower portion. One of the walls extend upwardly terminating at the ground level and the other wall extends vertically and then inclines at an angle terminating with a horizontal portion at the ground level.

[0012] An interior bearing liner includes a lower portion such as a channel and a pair of walls connected to the channel. Both walls extend vertically for some distance and then slope upwardly terminating in a straight portion at the ground level.

[0013] The liner is formed of a material strong enough, to keep the slurry and hold it therein, such as polymeric material like PVC.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:

[0015]FIG. 1 is a cross section of a perimeter footing of the prior art;

[0016]FIG. 2A is a cross section of a perimeter footing of the prior art without form board and stakes;

[0017]FIG. 2B is a cross section of an interior bearing footing of the prior art;

[0018]FIG. 3A is a cross section footing liner in accord with this invention;

[0019]FIG. 3B is a cross section of an interior bearing footing in accord with this invention;

[0020]FIG. 4 is cross section of the perimeter footing liner in place in the trench and concrete poured therein;

[0021]FIG. 5 is an isometric view of FIG. 4 without the stakes; and

[0022]FIG. 6 is another embodiment of this invention.

DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention may be best understood by reference to the attached drawings wherein FIGS. 1, 2A and 2B show the prior art, FIGS. 3A, 3B and 4 show a cross section of the invention, FIG. 5 shows an isometric view of the perimeter footing liner, and FIG. 6 illustrates another embodiment.

[0024] In FIG. 1 there is shown a trench 10 dug in the ground 40. The trench 10 should resemble the shape of a perimeter footing 22 having a lower portion such as a U-shaped channel 12A and a pair of walls 14A and 16A. One of the walls 14A extends vertically while the other wall 16A extends vertically and then inclines at an angle terminating in a horizontal portion 18 on which a concrete slab is poured, as well known in the art. However, in reality it is difficult to dig a footing in the soil and maintain the footing trench in its designed configuration so that it has uniform width and height along the trench 10. On occasions, portions of the soil often collapse, particularly those of the inclined wall section 16 as generally indicated by 16A and 14A and the soil even may partially cover the reinforcing rods 20 or have them resting on the soil 12A in the trench 10. As such, it may not be practical to obtain a concrete footing having the desired structure and geometry by simply pouring concrete slurry inside deformed trenches, as well as wasting concrete to fill the same.

[0025]FIG. 2A illustrates geometry of a concrete footing 22 positioned at a perimeter or a corner of a building. The footing 22 comprises a reinforced lower portion 24, a first vertical wall 23 extending above grade, and a second wall 26 having a short vertical section 28 and upwardly extending sloped second section 30. A third horizontal portion 32 becomes the bottom of a slab 62.

[0026]FIG. 2B shows a cross section of an interior footing 34. The footing includes a lower reinforced portion 36 and a pair of walls 38 and 41, each having a first portion 35 extending upwardly and thence a sloped second section 37 extending upwardly. A third portion 39 becomes the bottom of the slab 62.

[0027] In FIGS. 3A and 3B two embodiments of the present invention are shown. FIG. 3A is directed to a cross section of the present invention supporting a perimeter footing. A trench 10 dug in the ground in a predetermined shape, which has been determined to be an optimum structure for supporting the weight of the building and withstanding loads and other forces as well known. The footing liner 42 of this invention may be a plastic extrusion, for example PVC, or it may be molded to the intended size and shape of the concrete footing desired. The footing liner 42 has a U-shaped channel 43 having a first vertical wall 44 and a second wall 45. The second wall 45 has a vertical portion 46 extending upwardly, a sloped upwardly extending portion 47 and a third horizontal portion 48. Placement of liner 42 into trench 10 and then pouring concrete slurry inside the liner 42 molds the slurry into the designed shape of the footing accurately locating the reinforcing rods 20 in the concrete. When the slurry sets, it forms a concrete structure with substantially the designed geometry as shown in FIG. 2A

[0028]FIG. 3B shows an interior footing liner 49 for supporting the interior load bearing structure of a building. The interior footing 49 has the designed shape conforming to the concrete footing. The interior footing liner 49 is disposed inside trench 10 and has a U-shaped channel 50 with two walls 51 and 58 extending upwardly. Each wall 51 and 58 has a first vertical portion,51 and 55, a sloped wall extending upwardly 53 and 56, and a horizontal portion 54 and 57. When slurry is poured inside interior footing liner 49, the liner 49 holds the slurry therein and when the slurry is cured, a concrete footing 36, shown in FIG. 2B, is produced having the desired geometry and structure.

[0029]FIG. 4 shows a perimeter footing 22 formed inside a perimeter footing liner 42. A trench 10 is dug id the ground 40 and a supporting framework such as stakes 60 and form board 61 are installed about the trench 10. The liner 42 is then disposed inside the trench 10, reinforcing bars 20 are place inside supporting framework 60, and concrete slurry is poured inside the supporting framework 60 including the liner 42. The slurry is permitted to set into and form a concrete perimeter footing 22 and a concrete slab 62.

[0030]FIG. 5 is an isometric view showing a perimeter footing 42 disposed inside trench 10 and below a concrete slab 62, which is formed integral with footing 42. A supporting member such as form board 61 is disposed on top of the liner 42 and positioned by stakes 60 in the ground as shown in FIG. 4. Concrete slurry is then poured inside the liner 42 to form a perimeter footing below the outer edge portion of slab 62.

[0031]FIG. 6 shows a footing liner 64 to be used with brick veneers. The liner 64 includes a vertical wall 65 extending upwardly to a horizontal inwardly extending portion 66, which terminates at the surface of a form board 67 to limit the extent of the concrete pour. The other wall 68 extends substantially similar to the walls 45 and 58 shown in FIGS. 3A and 3B respectively, which normally used for frame construction. After pouring and setting of the concrete including the slab 62, a brick veneer wall 70 is constructed as illustrated.

[0032] While the invention has been described with respect to certain embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as they fall within the spirit and scope of the invention. 

What is claimed as new and what is desired to secure by Letters Patent of the United States is:
 1. A liner to preserve a predetermined shape and design of a concrete footing to be formed in a trench dug in a ground, said liner being disposable inside a trench for receiving slurry when set forming a concrete footing in said liner, said liner comprising a channel and a pair walls connected to said channel for holding a slurry therein.
 2. The liner of claim 1 wherein said pair of walls extend upwardly.
 3. The liner of claim 1 wherein one of said pair of walls includes three continuous portions, a first vertically extending portion, and a second slanted upwardly extending portion and a third horizontal portion.
 4. The liner of claim 1 wherein each of said pair of walls includes three continuous portions, a first vertically extending portion, and a second slanted upwardly extending portion and a third horizontal portion.
 5. The liner of claim 1 wherein one of said walls terminates adjacent ground level and another said wall extending spatially above said one wall.
 6. The liner of claim 3 wherein said third horizontal portion of one said wall extends spatially above said other wall.
 7. The liner of claim 4 wherein said second slanted portion of each said wall extends in opposite directions.
 8. A footing liner to preserve a predetermined shape and structure of a concrete footing to be formed inside said liner in a trench dug in a ground, said liner being disposable inside a trench for receiving concrete slurry therein, said liner forming a mold for slurry and permitting setting into a concrete footing.
 9. The liner of claim 8 further including a channel and a pair of upwardly extending walls connected to said channel.
 10. The liner of claim 9 wherein one of said pair of walls includes three continuous portions, a first vertically extending portion, and a second slanted upwardly extending portion and a third horizontal portion.
 11. The liner of claim 9 wherein each of said pair of walls includes three continuous portions, a first vertically extending portion, and a second slanted upwardly extending portion and a third horizontal portion.
 12. The liner of claim 9 wherein one said wall terminates adjacent ground level and another said wall extending spatially above said one wall.
 13. The liner of claim 10 wherein said third horizontal portion of one said wall extending spatially above said other wall.
 14. The liner of claim 11 wherein said second slanted portion of each of said wall extending in opposite direction.
 15. The liner of claim 8 further including a channel and a pair of upwardly extending walls connected to said channel, wherein each of said pair of walls include a slanted portion.
 16. The liner of claim 8 wherein said liner is formed of a polymeric material.
 17. A method for constructing a concrete slab for a building comprising the steps of: A. digging a trench for a footing in a ground around a perimeter of a building; B. installing a supporting frame about the trench; C. disposing a liner inside the trench to hold a concrete slurry; D. disposing reinforcing bars inside the supporting framework; and E. pouring concrete slurry inside the supporting frame including the liner and permitting the slurry to set into and form a concrete perimeter footing and a concrete slab.
 18. The method of claim 17 further including the steps of: E. digging another trench for a footing in a ground within the perimeter of a building; F. disposing another liner inside the another trench; and wherein step D includes pouring concrete slurry in he another liner and permitting the slurry to set into and form a load bearing wall footing beneath the slab.
 19. In a process for constructing concrete slab of a building including digging a perimeter footing in a ground; installing a supporting framework about the perimeter pouring a concrete slurry inside the framework; a method for preserving shape and design of the concrete footing comprising the steps of: A. disposing a pre-formed liner conforming in shape substantially to a cross-section of the footing located inside the footing before the step of pouring in the concrete slurry, and B. allowing the poured concrete slurry to cure to form the concrete footing and slab. 